Selective telephone system.



Nu. 689,!4I. Patented Dec. I7, |90l.

J. V. STUUT.

SELECTIVE TELEPHUNE SYSTEM.

(Application led Aug. 3, 1901.)

(No Modal.)

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JOHN V. STOUT, OF EASTON, PENNSYLVANIA.

SELTECTIVE TELEPHONE SYSTEM.

PECIFICATION forming part of Letters Patent No. 689,141, dated December 17, 1901.

Application led August 3, 1901. Serial No. 70.732. (No model.)

To L7/Z 1077.077?, it nur/y concern:

Be it known that I, JOHN V. STOUT, a citizen of the United States, residing at Easton,

lective,7 wherein any one of a number of sub-` stations on a circuit can be called up or signaled from a central station without disturbing the signal apparatus of any other station on the circuit.

For a selective system of electrical signaling to be a practical success the number of movements necessary to operate a signal should be reduced to the minimum, as additional movements not only cause loss of time, which means delay in answering calls, but they also increase the liability to error. Furthermore, it is important that the subscribers bell shall ring immediately upon the proper circuit being completed by the central operator without waiting for intermediate means, such as clockwork or other step-by-step movements, in connection with the signal to close the circuit, as such delays make prompt and perfect service difficult to obtain. It is also desirable that the substations shall not be hampered with relays, additional magnets, or devices of any kind foreign to the regular telephone call-bell, as each part added or additional t'orce employed increases the liability to get out of order. This invention embodies all the conditions above enumerated for a per feet selective signaling system.

The object of this invention is to providea selective telephone system for party-lines which shall have the desirable features hereinbefore enumerated and be free from the undesirable elements mentioned.

To the accomplishment-of the foregoing objects and such others as may hereinafter appear the invention consists in features ol connumber of substations connected t0 thelimbs.

In the drawing the letterA designates a centraloflice with so much ofthe same shown as will serve to illustrate the operation of my invention,cords,springjacks, p1ugs,&c.,t0 be used in connection with the parts shown being omitted for the sake ot' clearness, their operation being well understood in the art. Freni the central otice A two limbs X Y of a circuit pass out to several substations, of which six are illustrated and which,as shown, are designated by the letters B, C, D, E, F, and G. Within the central station is a number of calling-keys H, six in number being illustrated, one for eacl1substation,and numbered from 1 to G. An anvil or contact plate a", common to the keys 1 and 2, is connected by a wire 7 to the negative pole ot' a source of current, which for purposes otillustration is here shown as a battery I, the positive pole 0f which is connected to ground through a` comm utator or cu rrent-interrupter J; but any other suitable current-generator than a battery may be employed. A second anvil a2, common to the keys 3 and 4, is connected to the positive pole of a battery K, andan anvil a3 for the keys 5 and 6 is connected with the negative pole of a battery L, the positive pole of Which and the negative pole of battery K being connected to ground. 'lhe keys 3 and 5 are connected to each other by a'wire or other means S, and a similar wire 9 joins the keys t and 6. From the key connection S a wire 10 passes to the magnet M, which is connected with the limbY by a wire 2l. A wire 11 connects the keys 4 and G with a magnet N, which is also connected with the limb X by a wire 23. The armatures ot magnets M and Naro connected by a wire I5 with wire 7 of the battery I. The post or contact m' for the armature m2 ot the magnet M is connected by a wire 2O with the limb X, and the post or contact n for the armature n2 of ICO the magnet M connects with the limb Y by wire 24.

The calling instruments at the substations B and C and D and F. are substantially the same in general features of construction and mode of operation, although differing in the manner of wiring them to the limbs X` and Y, so that one will not be disturbed by ringing up any one of the Others, as will be hereinafter explained but so far as their details of construction are concerned they may vary from one another, and as an illustration of some of the changes that can be made in the details I have shown the ringers at the substations B and C somewhat different in details from those shown at stations D and E. The instruments, however, at stations F and G are like or similar to each other, but different both in construction and in operation from the instruments located at stations B, C, D, and F.. The instruments shown at the substations B and C are alike in features of construction; but when placed in position their armatures are oppositely located, as shown, and therefore a description of one will answer for both. In these instruments e and f represent two electromagnets connected, preferably, by a soft-iron yoke 0, although non-magnetic metal may be used. These magnets ,are supported in a fra-me S, on which is fulcrumed an armature fr, carrying a bellhammer B2, (the bells not being shown,) a

spring w being provided to norm ally hold the armature away from the magnet. Bolted to the frame S is a soft-iron piece p to serve as a polarizer for the armature r, said polarizer being preferably, but not necessarily, of angular form, and it may be secured to the frame by a nut, as shown. As illustrated, it is in contact with the core of the controlling or polarizing magnet f,- but that is not essential, as it will work without positive contact. The overhanging arm of the polarizer p carries an adjustable screw q, which is preferably of brass and which serves to limit the stroke of the bell-hammer. The form of instruments d' e' at the'substations D E is the same in most respects as the instruments at the substations B C; but instead of making the polarizing-piece angular it is in the form of a flat iron plate p', fastened to the brass plate F of the frame S, and I prefer to make the contact with the soft-iron core of magnet d by means of an iron screw y, threaded into the polarizing-piece 13'; but this screw may be dispensed with and if used need not be in positive contact with the core of the magnet, but is preferably so. The adjustable screw q is preferably made of brass and is threaded into the brass plate F' of the frame S. The instrument e at the substation Eis like that just described for the substation D, but when in position with its armature located opposite to the armature of the instrument at station D', as shown, the instruments at the stations F G may each respond to either polarity of current and in that particular differ from the instruments at any one of the other substations. In the instruments f g/ the magnet ct is preferably of one coil orhelix; but the other magnet Z) is preferably, for the purpose of compactness, what is known as a clubfooted magnet, and it has its bare core m joined to the core of the magnet, preferably by a soft-iron yokej. Pivoted to the frame S is a tongue ,'preferably of non-magnetic metal, and to which the armatures g and h for magnets at and b are attached, the armature h lying opposite to the bare core n and to the core of magnet d, while the armature g lies opposite to the core of magnet a. The tongue t is so adjusted by means of a spring w that magnet a when energized by the ringing or pulsatory current will attract its armature against the tension of said spring, and thus cause the bell to ring. The bellhammer B2 is connected to the pivoted tongue t'. It will be observed that the lever or tongue t', carrying the two armatures g and h, is fulcrumed between the two magnets a and b and that the armatures are separated or spaced by non-magnetic metal. Under this construction when the instrument is con-V nected to line, as hereinafter described, and the two magnets become energized, as hereinafter specified, the club-footed magnet will hold the bell-hammer in its retracted position,

so that the bell will not ring when the ringingcurrent for some one of the other substations 'energizes magnets at station F or G.

The wiring of the system in addition to the description already given is as follows: To the keys 1 and 2 are connected the limbs X Y of the line, respectively. At stations F and G the magnets at of the ringers f g have one wire connected to the branch of the circuit from which it is desired to ring the bell, while one wire of the club-footed magnet b is connected with the opposite branch of the circuit, the other wires of the two magnets at .each of the mentioned stations F G going to ground. The drawing illust-rates one wire of magnet ct at its station F, legged to the limb X by the wire 12, and one wire from the magnet ct of station G, legged by wire 13 to the limb Y, with one wire from the club-footed magnet b of station F, legged by wire 13 to limb Y, and one wire of club-footed magnet b at station G, legged by wire 12a to the limb X, and also one wire from each of the two magnets at stations F and G, as going to ground by wires 14 and 14a, respectively. At stations B and C the polarizing or controlling magnets fj of the ringers b c', respectively, have their outside wires extended to posts t* and then legged to the limbs Y X, respectively, and have the inside wires of said magnets extended to posts u and thence to ground, while the outside wires of the ringing-magnets e e? are extended to posts s and thence legged by the wires 16 and 17, respectively, to the limbs X Y, respectively, and the inside Wires of these magnets are extended to posts tand thence to ground. At stations D and E IOO IIO

the controlling or polarizing magnets cl d2 of the ringers d e', respectively, have their inside wires extended to posts u2 and thence legged to the limbs Y X, respectively, while their outside wires extend to posts o2 and thence to ground, and the ringing-magnets c c2 have their outside wires extended to posts s2 and thence legged by the wires 16 and 17, respectively, to the limbs X Y, respectively, and have their inside wires extended to the posts t2 and thence to ground, as illustrated. It will be observed that under this arrangement the inside wires of the two magnets at each of the stations B and C go to ground, While their outside Wires go to line, whereas at the stations D and E the outside Wires of the ringing-magnets go to opposite limbs of the line and the inside wires to ground, as in stations B and C, while the outside wires of the controlling or polarizing magnets go to ground and the inside wires to opposite limbs of the line, which is just the reverse to t-he running of the wires at stations B and C.

The apparatus constructed and connected as described operates as follows: When the operator depresses'the key 1, a pulsating current will ow from the source of current I through wire '7, anvil al, and key 1 to the limb X and through the magnets connected therewith to ground, causing the bell at station F to ring. When key 2 is depressed, the current is sent over line Y and through the magnets connected therewith to ground, ringing the bell at station G. These two devices will respond to either polarity of current, it being only necessary that the current shall be of sufficient strength to overcome the tension of the spring w. The other four ringers of the system are so adjusted by means of the retracting-spring vw that they will not be affected by this current. If the key 3 makes contact, a constant positive current will iiow from battery K and by wire 10 to magnets M and thence by wire 21 to the limb Y and through the magnets of the ringing instrument connected therewith to ground. This current is not of sufficient strength to attract any of the armatures of the ringers; but it will energize magnet M, so that it will attract its armature, and thus close a circuit from the source of current I through wire 15, armature mz, post or contact m', and wire 2O to the limb X. This will cause the bell at station B to ring, as the strength of the ringingmagnet e will be augmented by the controlling orpolarizing magnet f being energized by the current from battery K. The pole-piece j) polarizes the armature r when the controlling-magnet is energized, and thus increases or decreases the power of the ringing-magnet, depending upon the polarity of the poles of the two magnets. The ringer at station D, however, will not respond, because the inside wire of its controlling or polarizing magnet d is connected to line just the reverse of magnet f at station B, and therefore instead of increasing themaguetism in magnet c of station D it tends to neutralize it as Well as the armature through polarizer p. The bell at station F is prevented from ringing by the power of the spring w being supplemented by the attraction of magnet b, which is energized by the current from battery K. The ringer at station C will not respond, because the current from I passes to the controllingmagnet f2 and current from K to the ringingmagnet e2, and the current I being stronger than current K and only a portion of the magnetic lines passing to the rin gin g-magnet that portion plus the effect of current K being insufficient to energize magnet e2 sufficiently to attract the armature the bell at that station fails to ring, whereas at station B the full strength of current from I is applied to the ringing-magnet e, and this magnetism plus the magnetism received from magnetf produces sufficient strength in magnet e to actuate the ringer at station B. If key 5 is depressed, it completes the same circuit as key 3 and the magnet M will attract its armature and close circuit with limb X; but in this case the current will be negative from battery L instead of positive, as before, from key 3, so that a negative current will iiow over both wires,with the result that the bell at stationD willring,butthe oneat B will not, forthe reason that both currents being of the same polarity and flowing around the magnet at stationB in the same direction it produces similar poles in both magnets, which instead of increasing will reduce the strength of ringermagnet c at that station. The ringer f at station, F will not respond to this current for thesame reason as explained in describing the current from key 3. When keys 4 and 6 are depressed, the result is the same as by depression of keys 3 and 5, with this difference, that the magnet N will be energized, so that its armature n2 will be attracted and close circuit with the post or contact n', so that the current from I `will iow to limb Y and will ring the bell at either station E or C, according to the polarity of the current on the limb X. It will be noted from what has been so far stated that the same principle is involved in all of the ringers at the stations B, C, D, and E, the only difference being in the connections. With the inside wires of the controlling or polarizing magnets f f2 at stations B and C connected with ground and lthe outside wires connected to line and With the outside wires of the controlling or polarizing magnets at stations D and E connected to ground and the inside wires to line and all the magnets wound4 in the same direction, then if` the ringing-current-I is applied, say, to line X and one of the polarizing or controlling currents from battery K or L be applied to line Y the current from I will act in a complementary direction at one of the stations B or D and in au inductively-opposed direction at the other station-that is, it will develop poles of the same polarity at one station and of au oppo- ICC IIO

lov

site polarity at the other station. The magnets being thus wound and connected, it is evident that if a ringing-current is sent over, say, the line X and'another current over the line Y of a polarity that will increase the strength of the actuating-magnet c at station D such a current must necessarily have the reverse effect on the magnet e at station B, since the current passes around the polarizing-magnet at that station in the opposite direction to that of the polarizing-magnet at station D. In other Words, any combination of current which would produce similar poles in one set of magnets will cause dissimilar ones in the other set.

If desired, the ringing-current from I can be of greater strength for the ringers at the fourv stations B, C, D, and E than for the ringers at the stations F and G without affecting the latter, as the magnets b at stations F and G having two cores and the armature h being in close proximity to the same'it Will prevent the bell from ring-ing When-these magnets are energized by the current from either battery K or L, especially if provision is'made for getting the current from batter-y K or L on the line before the current from I is connected with the other branch of the line. This is one of the objects for using the magnets M and N, for with their use it is not possible for the current from I to have its circuit completed first when any of the keys 3, 4, 5, or 6 are pressed into contact, as the power of each ofthese magnets M and N depends entirely upon the current which passes over the line opposite to that on which the ringing is to be done. There are various Ways by which this can be accomplished Without the use of magnets; 'but Whatever the method may be I prefer to provide for having the magnet b of stations F or G energized in advance of the magnets a, connected with the other line, being energized by the current from I, in order to positively obviate any liability of trouble at the stations F G when one of the other stations is being called. With the system shown the currents from batteriesK and L should be continuous in order that the magnets M and N may not vibrate their armatures, and while I consider the form of the invention illustrated and described to be the most reliable and what eX- peri'ence has proved to me to be the best for practical use yet modifications can be made therein which will be comprised within the scope of the invention. l

The controlling-currents from batteries K andL will not ring any of the bells on their side of the circuit, for when the current from I is applied to the polarizing or controlling magnetsit will notincrease the power of their respective ringing magnets sufficiently for them to attract their armatures.

Preferably the several magnets, with the exception of magnets b at stations F and G, are made of one coil or helix, andI prefer to wind each one of the single magnets shown at the stations to about the same resistance as the combined resistance of the two magnets of the ordinary high-resistance bellthat is, the resistance t-o be sutiiciently high not to interfere with the talking-circuit. The magnets M and N, however, having little Work to do, are wound to a comparatively low resistance.

Under the arrangement shown I do not use a current-interrupter for theV batteries K and L, as I prefer to employ a constant or continuons current from the batteries and ofabout one-half the strength of the current from I, although this may be varied to some' degree.

I have illustrated and described the pre ferred details of construction and arrange ment of parts; but it is to be understood that the invention is not limited to such details in cases where-they may be varied and essentiall features of the invention still be employed, and so, also, it is to be understood that changes may be made in the exchange system and other features of my invention still be employed. It is also to be mentioned that-l various changes maybe made in the construction of the apparatus and the position of magnets. The main object in making them in the form shown is to have the devices conform as nearly as possible to the standard polarized rin gers as at present made, so as not to necessitate the enlarging or altering of the subscriber-s call-box or the changing of any of the parts of same. So, also, in the centraloffice system well-known changes could be made, so that it would not require three sources of current, 'as shown.

Having described my invention and set forth its merits, what I claim is l 1. Ina selective telephone system, a signaling device comprising a fulcrumed signaling member, a magnet to one side of the fulcrum of said member and connected to one limb of the line, a magnet to the other side of said fulcrnm and connected with another limb of the line, and a spring, one of said magnets when energized serving to move the signaling member, and the other magnet and springserving to hold the signaling member in its normal position against the influence of the other magnet when both magnets are energized, substantially as described.

2. In a selective telephone system, a signaling device comprising a fulcrumed signaling member, a magnet to one side of the fulcrum to said lever, a club-footed magnet to the other side of said fnlcrum, and a spring, one of said magnets being connected to one limb lof the line and when energized serving to move the signaling member, the club-footed magnet being connected to the other limb of the line and together with the spring serving to hold the signaling member against the in- IOO IIO

luence of theother magnet when both mag- .p x

nets are energized,substantially as described.

3. In a selective telephone system, a signaling device comprising a fulcrumed signaling member and two magnets, one for actuating and the other for controlling the movement of said member, the actuating-magnet and its armature being normally neutral but the armature polarized when the controllingmagnet is energized, the actuating-magnet having its power augmented or decreased by the magnetism of the other magnet according to the polarity or direction of current through the magnet, substantially as described.

4. In aselective telephone system, asignaling device comprising a fulcrumed signaling member and two magnets, one for actuating and the other for controlling the movement of said member, one of said magnets being connected to one limb of the line and receiving current from a source to partially energize the magnet, the othenmagnetbeing connected to another limb of the line and receiving current from another source and transferring its magnetism to the other magnet to augment the power of the latter and render it active, substantially as described.

5. In a selective telephone system, a signaling device comprising a fulerumed signaling member and two magnets, one for actuating and the other for controlling the movement of said member, one of said magnets when sufficiently energized serving to move said signalingmember, and the other magnet having a polarizer within its magnetic field and serving to control the magnetismof the actuating-magnet, substantially as described.

(i. In a selective telephone system, a signaling device comprising a fulerumed signaling member and two magnets, one for actuating and the other for controlling the movement of said member, one of said magnets being connected to one limb of the line and receiving current from a source to partially energize the magnet, the other magnet being connected to another limb of the line and receiving a current from another source and serving to control the activity of the other magnet, and a magnet in the circuit over which the controlling magnet receives its current and adapted to close the circuit of the other source of supply after the current for the controllingmagnet is on its line, substantially as described.

7. In a selective telephone system having a number of stations, a signaling device for each station comprising a fulcrumed signaling member and two magnets, one for actuating and the other for controlling the movement of said member, one of said magnets being connected to one limb of the line and receiving current from a suitable source, the other magnet being connected to another limb of the line and receiving current from another source, the magnets at the stations being so wound or connected that when the currents from the separate sources are thrown upon the lines there will be developed poles of the same magnetic polarity at one station and of an opposite polarity at another station and the signal will be given' only7 at the station where the polarity is such as to render the magnet active, substantially as described.

8. A selective telephone system comprising a number of stations, two ot said stations being provided each with a pair of magnets one of which is connected-to one limb of the line and the other with the opposite limb, and a fulcrumed signaling member foreach pair of the magnets, one magnet of each pair when energized serving to move its signaling member and the other magnet serving to hold the signaling member in its normal position against the inuence of its companion magnet when both magnets are energized, the other stations being each provided with a pair of magnets and a signaling member, the pair of magnets at each station being connected with opposite limbs of theline and to ground, the inside wire of one ot' the magnets at some of the stations extending to line and the inside wire of its companion magnet to ground and the inside Wires of the pair of magnets at the other stations extended to ground, one of the magnets of each of said stations having its power augmented or decreased by the magnetism of its companion magnet according to the polarity or direction of current through the magnet, separate sources of current-supply, and means for sending the current to the con trolling-magnet of each pair of magnets in advance of closing the circuit through which the current is sent to the other magnet of the pair, substantially as described.

9. A selective telephone system, comprising a number of stations, two of said stations being provided each with a pairof magnets one of which is connected to one limb of the line and the other with the opposite limb, and

IOD

a fulcrumed signaling member for each pair ofthe magnets, one magnet of each pair when energized serving to hold the signaling member in its normal position against the influence of its companion magnet when both magnets are energized, the other stations being each provided with a pair of magnets and. a signaling member, the pair of magnets at each of said stations being connected with opposite limbs of the line and to ground in such manner that when the currents of separate circuits are thrown upon the lines there will be developed poles of the same magnetic polarity at one station and of an opposite polarity at another station and the signal will be given only at the station where the polarity is such as to render active the magnet at that station, one of the magnets at each of said stations having its power augmented or decreased by the magnetism of its companion magnet according to the polarity or direction of current, through the two magnets, and means for sending the current to the circuit of the controlling-magnets in advance of closing the circuit through which the current is sent to the other magnets, substantially as described.

10. A selective telephone system comprising a number of stations, two of said'stations being provided with signaling-magnets cach connected with both limbs of the line and one of them adapted to be energized to activity by a current insuiticient to actively energize the magnets of other stations on the line, a pair of signaling-magnets at each ofthe other stations connected to both limbs ot' the line and requiring for energization a combination of currents which will produce similar poles in the set of magnets at one station and dissimilar poles in the magnets of another station, means for sending the required polarity of current over the line to render active the magnets at any desired station to be signaled without rendering active the magnets of the other stations, means for getting one current to the magnets in advance of the other current necessary for giving the signal, and electromagnetic means for preventing the magnets which are responsive to either polarity from being energized into signaling activity by the currents which give the signals at lthe other stations, substantially as described.

l1. A selective telephone system, comprising a number of stations, two of said stations being provided each with a pair of magnets connected to opposite limbs of the line and to ground,the otherstations being provided each with a pair of magnets connected to the limbs of the line and to ground in'such manner that there will be developed poles of the same magnetic polarity at onestation and of an opposite polarity at another station, a source of current for the magnets responsive to either polarity, other sources of current and means for throwing one or the other of the same onto line, and means for bringing current from the first-mentioned source of currentonto line after the current from one of the other is brought onto line to form a current of the same or different polarity according as one or other polarity of current is brought onto line from one of t-he other sources of current, substantially as described.

12. In combination with a central-ofce system forselective telephone signaling, a ringing and a controlling current, and means at the central station for automatically closing the ringing-circuit to a subscribers line after the controlling-circuit to same has been completed, substantially as described.

13. In combination with a central-station system for selective telephone signaling, an actuating and a controlling current, a magnet at the central station in the circuit of the controlling-current and adapted to complete at the central station, and means for closing the circuit of the controlling-current through one of said magnets thence to one of the branches oi` a subscribers circuit, said magnet when so energized completing the circuit ofthe actuating-current to the other branch ot' the subscribers circuit, substantially as described.

15. In a selective telephone system,l a central station, wires extending from said station to subscribers stations, call-.bells or ringers at the substations, a ringing -magnet connected with one branch of a circuit, an armature for said magnet, and a second magnet connected with the other branch of the circuit, said magnet being out of the attractive field of the armature and adapted when'energized to control the power of the ringing-magnet, substantially as described.

16. In a selective telephone system, a circuit extending from a central station and vhaving a plurality of subscribers stations,

each containing a ringer or bell, connected with same, a magnet of the ringer or call-bell at a station legged to one of the branches of a circuit and adapted to ring the bell, a second magnet connected to the other wire of the circuit, a pole-piece within the magnetic field of the second magnet and Iextending'to or over the armature of the ringing-magnet for the purpose of polarizing said armature when the controlling-magnet is energized, substantially as described.

17. In a selective telephone system, a central station, wires leading therefrom and having a series of substations connected with same, responsive devices at the subscribers stations comprising a fulcrumed member and two magnets, one of said magnets being legged to one limb of a circuit and adapted to actuate the signaling device, the second magnet connected to the other limb of the circuit, and an iron pole-piece or polarizer in magnetic contact with the second magnet for the purpose of polarizing the armature of the actuating-magnet when the controlling-magnet is energized, substantially as described.

18. In a selective telephone system, a central station, subscribers circuits terminating therein and having a series of substations bridged across the same, responsive devices at the substations comprising a signaling member and two magnets, one of said magnets being adapted to actuate the signal and connected with one limb of a circuit, and a second magnet connected with the other limb of the circuit and adapted to augment or diminish the power of the actuating-magnet and thereby control the same when both` are energized, substantially asset forth.

19. In a selective telephone system, a central station and metallic circuits terminating therein,a plurality of substations connected in multiple with a circuit, signaling devices at the stations comprising a fnlcrumed bellhammer, a spring, and two magnets, one of said magnets being adapted to actuate the ICO IIO

bell-hammer and connected with one branch l by actuate the signal at the station called, of a subseribers circuit, the second or e011- the said second magnets at the other stations trolling magnet connected with the other `on the eireuit serving to prevent the movebranch of the circuit, a ground or return conment of the bell-hammer at their respective 15 5 necton between said magnets, a source of stations, substantially as set forth.

electrical energy of predetermined strength In testimony whereof I affix my signature servingto energize the actuating-magnet, and in presence of two witnesses. a Current of lower tension for energizing the JOHN V. STOUT. y other magnet and by its means increasing the xo power of the actuating-magnet sufficiently to overcome the tension of the spring, and there- Witnesses:

E. I-I. SHAWDE, ANNA C. SHAWDE. 

